I received a warning about token replacement. Do I need a new keyset?

Normally, in DevZone, you go here to get a new user token :
https://developer.ebay.com/DevZone/account/tokens/

You select prod envrionment, and select "Key Set 1" and hit the "get user token" button.

You then go thru the eBay sign-in (Auth & Auth) process.

You then come back to DevZone, with token data filled in, and click the "save token" button. This pops up a JavaScript warning that says :
"You are about to replace an existing token. Do you want to continue?"

This is a DevZone limitation. Although you can have many user tokens which will work for a given keyset, DevZone currently is only able to retain one user token per keyset. This is basically a "storeage" issue in DevZone and has nothing to do with how keysets and tokens operate.

Depending on what you're doing, eBay recommends to store tokens as needed in a secure manner (ex. protected file) on your system.

For example :

eBayID UserToken
------ ------------------
user1 AAA*...(up to two thousand chars...)
user2 ABB*...(up to two thousand chars...)

If you're working with a larger number of users, you may want to store tokens in a secure manner in a database.

In summary, you can create any number of user tokens for a given keyset, but DevZone can only store one token per keyset, and that's why you received the warning about replacing a token.